Computer program updates may be distributed in the form of patches. A patch may be provided by a file comprising one or more fragments of computer code (e.g., source code or executable code) and/or data. A source code patch may be provided by a file comprising a listing of differences of an original source code file and a corresponding updated source code file. A specialized program (e.g., GNU patch utility) may apply one or more patch files to a source code tree on a target computer system, producing patched versions of the affected source code files.